Untitled Flashcards Set

Geomorphology

Study of landforms and how they form.

Alfred Wegener

Proposed the theory of continental drift and the existence of a supercontinent (Pangaea).

Inner Core

The solid iron and nickel center of the Earth.

Pangaea

Supercontinent that existed 300 million years ago.

Basalt

Primary rock of oceanic crust.

Plate Divergence

When two continental plates pull apart.

Quartz

A common rock-forming mineral.

Mid-Oceanic Ridge

Ridge-like feature formed by magma upwelling at a rift zone.

Lava

Molten rock on Earth's surface.

Extrusive Igneous Rock

Formed from cooling lava.

Subduction

One lithospheric plate forced beneath another.

Lithification

Process of cementing and compacting rock.

Primary Waves

Compressional seismic waves.

Calcite

Dominant mineral in limestone.

Cinder-Cone Volcano

Small, steep volcano formed by solidified magma fragments.

Metamorphic Rocks

Rocks formed from heat and pressure without melting.

Caldera

Large depression caused by volcanic activity.

Earth’s Age

Approximately 4.7 billion years.

Mauna Loa

Largest volcano on Earth.

Geologic Time Order

Eons > Eras > Periods > Epochs.

Composite Volcanoes

Explosive volcanoes formed after several eruptions.

Holocene Epoch

About 10,000 years old.

Sandstone

Sedimentary rock formed from compacted sand grains.

Mantle

Layer between the outer core and crust, composed of silicate rock.

Isostasy

Equilibrium between lithosphere and asthenosphere.

Transform Plate Margin

Boundary where plates move horizontally relative to each other.

Moment Magnitude Scale

Measures earthquake magnitude based on fault movement and rock strength.

Caldera

Large volcanic depression from explosion or collapse.

Hotspot

Stationary zone of magma upwelling causing volcanism.

Minerals

Naturally occurring substances with a crystalline structure.

Gravity

Primary agent of mass wasting.

Oxbow Lake

Abandoned stream channel cut off by meandering.

Chemical Weathering

Breakdown of rock due to chemical reactions.

Exfoliation

Physical weathering where rock sheets flake off due to temperature changes or unloading.

Physical Weathering

Also called mechanical weathering.

Radial Drainage

Drainage system typical of volcanoes.

Denudation

Long-term erosive process reducing elevation of landforms.

Solifluction

Soil movement in Arctic environments due to freeze-thaw cycles.

Angle of Repose

Maximum angle at which loose material can rest without sliding.

Avalanche Track

Zone where avalanche causes the most destruction.

Aggradation

Accumulation of sediment in a stream.

Delta

Low, level plain formed where a stream enters a still body of water.

Carbonation

Chemical weathering where carbonic acid dissolves rock.

Talus

Rock debris at the base of a cliff due to rockfall.

Trunk Stream

Primary stream of a drainage basin.

Oxidation

Chemical weathering where oxygen combines with metallic elements.

Suspended Load

Sediment floating in a stream.

Confluence

Point where two streams join.

Salt Crystal Growth

Weathering where salt weakens rock cement through evaporation.

Drainage Basin

Area that contributes runoff to a stream.

Cutbank

Steep slope formed by erosion at the outside of a meander.

Cap Rock

Resistant rock layer protecting underlying layers from erosion.

Floodplain

Low-lying area that floods during heavy rainfall.

Knickpoint

Rapid or waterfall in a stream.

Natural Levee

Ridge formed by sediment deposition during flooding.

Flows

Mass-wasting events involving very wet material.

Biological Weathering

Breakdown of rock by plants and animals.

Frost Wedging

Expansion of freezing water in cracks causing rock breakage.

Sheet Runoff

Water flowing in sheets toward a drain.

Soil Creep

Slowest form of mass wasting.

Field Capacity

The condition when pore spaces in soil are completely filled with water.

Karst Topography

A landscape characterized by caves and soluble rock features.

Aquifer

A geological formation that contains a suitable amount of water for human use.

Stalactites

Hanging rods of minerals (e.g., calcium carbonate) formed in caves.

Water Table

The top of the saturated zone in the ground.

Sandy Sediments

The largest aquifers occur in regions with abundant sandy sediments.

High Plains (Ogallala) Aquifer

The most heavily utilized aquifer in North America.

Tower Karst

A type of karst topography occurring in humid subtropical areas with thick limestone beds.

Subsidence

The sinking of a surface due to loss of support from underlying water, soils, or strata.

Hygroscopic Water

Soil water held so tightly by sediment grains that it is unavailable for plant use.

Saturated Zone

The zone below and including the water table where pore spaces are completely filled with water.

Capillary Water

Water that moves upward through the unsaturated zone.

Artesian Well

A well where water rises to the surface through natural pressure in a confined aquifer.

Spring

A place where water naturally seeps out of the ground.

Sinkhole

A topographic depression formed when underlying rock dissolves, causing surface collapse.

Groundwater

Water that fills the cracks and spaces in underground soil and rock layers.